Message-ID: <eb0df15a-150e-8c7f-4f91-fc1c1442cb76@gmail.com>
Date:   Thu, 9 Feb 2023 16:58:34 +0800
MIME-Version: 1.0
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Subject: Re: [PATCH] net: openvswitch: fix possible memory leak in
 ovs_meter_cmd_set()
To:     Eelco Chaudron <echaudro@redhat.com>
Cc:     pshelar@ovn.org, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, xiangxia.m.yue@gmail.com,
        netdev@vger.kernel.org, dev@openvswitch.org,
        linux-kernel@vger.kernel.org
References: <20230208071623.13013-1-hbh25y@gmail.com>
 <155E8FC1-746B-4BA4-BA80-60868B076F00@redhat.com>
Content-Language: en-US
From:   Hangyu Hua <hbh25y@gmail.com>
In-Reply-To: <155E8FC1-746B-4BA4-BA80-60868B076F00@redhat.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 9/2/2023 16:26, Eelco Chaudron wrote:
> 
> 
> On 8 Feb 2023, at 8:16, Hangyu Hua wrote:
> 
>> old_meter needs to be free after it is detached regardless of whether
>> the new meter is successfully attached.
>>
>> Fixes: c7c4c44c9a95 ("net: openvswitch: expand the meters supported number")
>> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
>> ---
>>   net/openvswitch/meter.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
>> index 6e38f68f88c2..e84082e209e9 100644
>> --- a/net/openvswitch/meter.c
>> +++ b/net/openvswitch/meter.c
>> @@ -448,8 +448,10 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
>>   		goto exit_unlock;
>>
>>   	err = attach_meter(meter_tbl, meter);
>> -	if (err)
>> +	if (err) {
>> +		ovs_meter_free(old_meter);
>>   		goto exit_unlock;
> 
> It would be nicer to add another goto label like exit_free_old_meter.
> 
> +	if (err)
> +     	goto exit_free_old_meter:
> 
> exit_free_old_meter:
>      ovs_meter_free(old_meter);
> exit_unlock:
> 	ovs_unlock();
> 	nlmsg_free(reply);
> exit_free_meter:
> 
> 
> Or maybe it would be even nicer to free the old_meter outside of the global lock?
> 
>> +	}
>>
>>   	ovs_unlock();

I get it. I will send a v2.

Thanks,
Hangyu
>>
>> -- 
>> 2.34.1
>